####018003963#### FXUS64 KSJT 131830 AFDSJT Area Forecast Discussion National Weather Service San Angelo TX 1230 PM CST Sat Dec 13 2025 ...New SHORT TERM... .KEY MESSAGES... - Temperatures will be well-above normal this afternoon. - Stronger Cold frontal passage tonight with gusty winds and colder temperatures for Sunday. - Another week of warm weather will follow cool temperatures on Sunday. && .SHORT TERM... (This evening through Sunday) Issued at 1225 PM CST Sat Dec 13 2025 Low clouds and fog have continued to rapidly dissipate early this afternoon and will have mostly sunny skies and warm conditions for the afternoon. All that changes tonight as a fairly strong cold front moves through West Central Texas. Surface pressure gradient is impressive late tonight into Sunday morning, and model blends have generally underdone wind speeds on these occasions. Have boosted wind speeds for late tonight and Sunday. Highs on Sunday will be a challenge, based largely on how quickly low clouds trapped under the thermal inversion can get mixed out and can dissipate. GFS and some of the high res models like the RRFS dissipate the clouds fairly quickly and allow temperatures to climb into the upper 40s to near 50. Others like the NAM12 and HRRR play a middle ground with highs mainly in the mid 40s. Finally, the usually reliable in these situations NAM keeps temperatures in the mid/upper 30s (especially across the Concho Valley around San Angelo). Not going to go that cold, but will play the middle ground for now and keep temperatures in the low to mid 40s across the area for now. This actually puts it in line with the probabilistic data from the HREF on Sundays temperatures. && .LONG TERM... (Sunday night through next Saturday) Issued at 1219 PM CST Sat Dec 13 2025 After a sharp, but brief cool-down on Sunday and a cold morning Monday, we will rebound back up into the upper 50s to lower 60s across the area Monday afternoon. Through the middle of the week, a weak upper level trough will move across the area, potentially resulting in some mid and upper level clouds. However, no precipitation is expected with this feature. And at the surface, flow will remain southerly, so temperatures are expected to warm through mid-week. A strong trough will move through the central plains region later in the week, pushing a weak cold front through west central Texas Thursday, but temperatures will remain above normal. Southerly winds will quickly return Friday into Saturday, with highs approaching 80 degrees by next weekend. && .AVIATION... (18Z TAFS) Issued at 1114 AM CST Sat Dec 13 2025 Improving conditions late this morning as the fog and low clouds break up and dissipate. Will use the latest satellite imagery to determine the exact timing but all areas should be VFR by mid afternoon. Stronger cold front still set to move across the area late tonight and bring gusty north winds in its wake. Gusts at or above 25 kts likely at most locations. Models have their differences in cloud cover behind the front, generally on how low the cigs are and how long they persist. Will lean towards a NAM solution on much of this simply because it usually does better in these situations, but fully expect updates to be needed as additional data comes in. && .PRELIMINARY POINT TEMPS/POPS... Abilene 29 43 30 62 / 0 0 0 0 San Angelo 34 44 35 62 / 0 0 0 0 Junction 36 46 32 63 / 20 0 0 0 Brownwood 31 43 27 59 / 0 0 0 0 Sweetwater 29 42 33 62 / 0 0 0 0 Ozona 36 43 37 57 / 0 0 0 0 Brady 35 43 31 60 / 10 0 0 0 && .SJT WATCHES/WARNINGS/ADVISORIES... None. && $$ SHORT TERM...07 LONG TERM....20 AVIATION...07 ####018008087#### FXUS64 KHUN 131831 AFDHUN Area Forecast Discussion National Weather Service Huntsville AL 1231 PM CST Sat Dec 13 2025 ...New AVIATION... .KEY MESSAGES... Updated at 1214 PM CST Sat Dec 13 2025 - There is a 15-40% chance for light rain or drizzle Saturday night with very light (less than 0.05 inches) accumulation expected. - A Cold Weather Advisory has been extended back in time for Wind Chill values of 5 degrees or below for Lincoln, Moore, and Franklin counties from midnight tonight through 6pm Sunday. -A Wind chill Advisory remains in effect for our northern Alabama counties and these southern middle Tennessee counties from 6 PM on Sunday through 6am on Monday. - Sub freezing temperatures will move into the area towards daybreak on Sunday and continue through Monday morning. && .NEAR TERM... (Rest of Today and Tonight) Issued at 1214 PM CST Sat Dec 13 2025 Sunny skies continue across northern Alabama this morning. The insolation and weak warm air advection in the boundary layer has allowed temperatures to climb into the mid 50s to lower 60s already this morning. The warmest temperatures are in place south of the Tennessee River near Vinemont, AL and Albertville, AL. In these locations temperatures have already reached 64 and 66 degrees respectively. Mostly cloudy conditions will push into the area very late this afternoon (after 3 or 4 PM). This cloud cover will occur as a weak surface low along the arctic cold front that stretches from the northern Ohio Valley SW into SW Missouri/far eastern Oklahoma pushes southeast this afternoon towards the Tennessee Valley region. Some decent isentropic lift is seen in the saturated cloud layer ahead of and slightly behind this front as it moves southeast this afternoon into tonight. Overall, the saturated cloud layer is a bit deeper in the newest models runs than yesterday's runs. Not alot of lift seen through isentropic lift below 285K in this cloud layer, but near the top of that layer (~295K), better lift is seen this afternoon and early this evening. This lift will likely lead to evaporative cooling very late in the afternoon, which will likely keep highs form reaching the upper 60s, despite abundant sunshine. Also, it looks like isolated to scattered rain showers will develop in response to this lift. Not looking at heavy rainfall, but scattered light rain showers are expected, especially south of the Tennessee River. With abundant sunshine much of the day, highs will likely climb into the mid 60s in many locations south of the Tennessee River. New runs continue to push this precipitation and the arctic air behind the front quickly east towards the Tennessee Valley tonight. However, the truly arctic air will likely lag behind the frontal boundary and move into southern middle Tennessee and northern Alabama towards daybreak. This should keep any wintry precipitation out of the forecast, as the isentropic lift even at 295K moves east of the area between 10 PM and midnight tonight. && .SHORT TERM... (Sunday through Tuesday) Issued at 1214 PM CST Sat Dec 13 2025 The bigger issue will be the wind chills, as a strong 925 mb jet of 20 to 30 knots develops near and just behind the arctic front towards daybreak on Sunday and remains in place through much of the day on Sunday. Sustained winds of 10 to 15 mph with gusts around 25 mph are expected due to the wind energy associated with the 925 jet aloft. This will drive wind chill values to between 0 and 5 degrees in portions of our southern middle Tennessee counties. Thus, the Cold Weather Advisory was extended back in time for Lincoln, Moore, and Franklin counties in Tennessee from midnight tonight through 6 PM on Sunday. Not much relief is expected on Sunday as actual highs will be hard pressed to climb above the 30 degree range, except maybe in Cullman, Marshall, or Dekalb counties in AL. With the 925 mb jet remaining over the area and only weakening to 20 to 25 knots, windy conditions will continue. Though wind chill values will climb into the teens in the afternoon, it is a brief respite. Temperatures will fall quickly with the loss of daytime heating and continued cold air advection Sunday night. Temperatures should drop into the 10 to 15 degree range in most locations by the evening hours. Though winds will not be as strong they still will be between 5 and 10 mph much of the night, with some gusts in higher elevations of NE AL to between 15 and 20 mph lingering through daybreak on Monday. This should drive wind chill values to around 5 degrees across many areas of northern Alabama and our southern middle Tennessee counties (A few locations such as higher elevations of NE Alabama and southern middle Tennessee could see a few wind chill values as low as 0 degrees). Thus, keeping the Cold Weather Advisory in effect for all of our northern Alabama and southern middle Tennessee counties from 6 PM on Sunday through 6 AM on Monday morning. Temperatures should warm into the low 40s Monday afternoon. However, one more cold night is expected Monday night as lows drop into the 20s. Luckily winds will be light, so winds chills will not be much of a concern. && .LONG TERM... (Tuesday night through Friday) Issued at 1058 PM CST Fri Dec 12 2025 This warming trend will continue through mid week as a result of upper level ridging and subsequent sfc high pressure shifting over the area. While the majority of the long term period remains dry, rain chances return by late in the week as an upper level shortwave and weak LLJ shifts eastward over the area. We will continue to monitor this system in future updates, however, the greater rain chances seem to remain north of our area at this time (where the LLJ is stronger). Therefore, continued with blended guidance of low to medium PoPs. && .LONG TERM... (Tuesday night through Friday) Issued at 1058 PM CST Fri Dec 12 2025 This warming trend will continue through mid week as a result of upper level ridging and subsequent sfc high pressure shifting over the area. While the majority of the long term period remains dry, rain chances return by late in the week as an upper level shortwave and weak LLJ shifts eastward over the area. We will continue to monitor this system in future updates, however, the greater rain chances seem to remain north of our area at this time (where the LLJ is stronger). Therefore, continued with blended guidance of low to medium PoPs. && .AVIATION... (18Z TAFS) Issued at 1231 PM CST Sat Dec 13 2025 VFR conditions are expected at both terminals through 23Z at KMSL and 00Z at KHSV. CIGS should lower between 00Z and 05Z at times into the MVFR realm. However, not sure if these conditions will be predominant. They may be more closely tied to scattered light rain showers that develop near or impact the terminals. Thus, only include these MVFR conditions in a PROB30 group associated with -SHRA chances (KMSL - from 00Z to 04Z/KHSV - from 01Z to 05Z) for now. Variable winds of 5 knots or less should pick up early this evening becoming northwesterly and increasing to between 10 and 15 kts with gusts to around 20 kts possible (especially towards daybreak on Sunday). VFR conditions should return to the KMSL terminal after 6Z and the KHSV terminal after 9Z, with some lingering clouds around 5000 feet before clearing around daybreak. && .HUN WATCHES/WARNINGS/ADVISORIES... AL...Cold Weather Advisory from 6 PM Sunday to 6 AM CST Monday for ALZ001>010-016. TN...Cold Weather Advisory from midnight tonight to 6 AM CST Monday for TNZ076-096-097. && $$ NEAR TERM...KTW SHORT TERM....KTW LONG TERM....HC AVIATION...KTW ####018008693#### FXUS62 KTAE 131831 AFDTAE Area Forecast Discussion National Weather Service Tallahassee FL 131 PM EST Sat Dec 13 2025 ...New SHORT TERM, LONG TERM, AVIATION, MARINE, FIRE WEATHER, HYDROLOGY... .KEY MESSAGES... Issued at 128 PM EST Sat Dec 13 2025 - Another round of fog, especially across the Florida Big Bend into south-central Georgia, is expected tonight ahead of the cold front. - A Freeze Watch for a Hard Freeze for temperatures at or below 25 degrees is in effect for our Alabama and Georgia counties Sunday night into Monday morning. - A Freeze Watch for temperatures below 32 degrees is in effect for the Emerald Coast and coastal Franklin County Sunday night into Monday morning. - A Cold Weather Advisory is in effect Sunday night into Monday morning across the area for wind chills between 15 and 20 degrees in Alabama and Georgia and 16 to 24 degrees for Florida. - Additional Cold Weather Products likely needed Monday night into Tuesday morning. && .SHORT TERM... (This Evening through Sunday) Issued at 128 PM EST Sat Dec 13 2025 Cold front nears our area tonight and will push through during the day Sunday. A few showers are expected along the front, especially across Southeastern Alabama, later tonight into Sunday morning. Even if we do get rain, not a whole lot is expected with less than 0.10 inch forecast. Temperatures will be tricky across the region on Sunday. Our northern counties will likely experience the warmest temperatures in the morning with dropping temperatures throughout the day. Meanwhile, the fog may limit heating across the Florida Big Bend and south-central Georgia before breaking just ahead of the front; how much we'll be able to warm there before the Cold Air Advection (CAA) from the front remains uncertain. So, admittedly, there is lower confidence than normal for this temperature forecast. That said, we're forecasting highs for Sunday near 60 across our northern Georgia and Alabama counties and the upper 60s to near 70 farther south before the front drops temperatures behind it. && .LONG TERM... (Sunday night through next Friday) Issued at 128 PM EST Sat Dec 13 2025 Cold. That sums up the forecast to start the period. Strong CAA will be ongoing Sunday night with air temperatures dipping into the middle to upper 20s for most of the area away from the coast, where you'll be closer to 30. As a result, have gone ahead and issued a Freeze Watch for the Emerald Coast and coastal Franklin county, where the Freeze (for temperatures between 26-32 degrees) program is ongoing. And there is a Freeze Watch for a Hard Freeze (for temperatures at or below 25 degrees) for our Alabama and Georgia counties. Northerly to northeasterly breezes at 10 to 15 mph, gusting to near 20 mph, will create Cold Weather Advisory Wind Chills, or below 25 degrees in Florida and below 20 degrees in Alabama and Georgia. Due to increased confidence and collaboration with neighbors, have gone ahead and issued a Cold Weather Advisory for all of our area for Sunday night into Monday morning. Monday afternoon will be cold with highs struggling to get out of the 40s across the entire region. Another cold night is in store Monday night as the surface high settles nearly overhead and should allow for decent radiational cooling. Additional cold weather products, either Freeze Warning for a Hard Freeze or Cold Weather Advisories, may be needed. A note about Monday night/Tuesday morning: subtle moisture increase around 900mb could throw a wrench into the forecast, especially for the eastern third of our area, or south and east of a line from near Tifton to Apalachicola in the form of some cloud cover. A warming trend commences Tuesday afternoon with highs back near 60 Tuesday and near 70 again Thursday and Friday. Low chances for rain return later next week as an H5 shortwave races over the region. However, moisture return appears meager at this time and have capped rain chances at 20 percent. && .AVIATION... (18Z TAFS) Issued at 128 PM EST Sat Dec 13 2025 VFR conditions prevail through the afternoon but another round of IFR/LIFR cigs and visibilities are possible after 06z at all terminals, especially across Florida Big Bend terminals and into south-central Georgia ahead of a frontal system. The front should pass through the area beginning at ECP/DHN around 12z with northwesterly winds taking over quickly. The front should pass through ABY/TLH/VLD by 15/16z. Conditions will quickly improve to MVFR behind the front with VFR conditions like developing by the later afternoon at area terminals. Expect frequent 25 knot gusts tomorrow afternoon behind the front. && .MARINE... Issued at 128 PM EST Sat Dec 13 2025 Northerly winds develop behind a strong cold front sweeping through the northeastern Gulf Sunday. A Gale Warning is now in effect for Sunday afternoon through Sunday evening for the Gulf waters west of Apalachicola. A Small Craft Advisory was issued for the waters east of Apalachicola later Sunday afternoon and will continue through Monday morning; Advisory level winds will follow the Gale warning for waters west of Apalachicola. Light to moderate easterly winds are forecast later Monday night with more favorable marine conditions returning to the northeastern Gulf for the middle of the week. && .FIRE WEATHER... Issued at 128 PM EST Sat Dec 13 2025 Southwesterly transport winds rapidly turn northerly following the passage of a cold front Sunday morning into the afternoon. This cold front will bring a few showers to our Alabama districts, but the chance for a wetting rain is less than 5 percent. Very low dew points filter in Sunday night into Monday morning with dew points in the single digits forecast for much of our Alabama and Georgia districts along with breezy northerly winds. MinRH values Monday afternoon will be in the 20 to 30 percent range with temperatures in the 40s. Low dispersions are a concern Tuesday thanks to high pressure overhead. Another round of patchy to areas of dense fog is forecast tonight into Sunday morning ahead of the cold front. && .HYDROLOGY... Issued at 128 PM EST Sat Dec 13 2025 While a few showers are forecast later tonight into early Sunday morning ahead of a cold front, rainfall totals are forecast to be less than 0.10 inch. There is another chance for rain later in the work week, but chances are low, around 20 percent, at this time. No flooding is anticipated the next several days. && .SPOTTER INFORMATION STATEMENT... Spotter activation is not requested. However, spotters are always encouraged to safely report significant weather conditions when they occur by calling the office or tweeting us @NWSTallahassee. && .PRELIMINARY POINT TEMPS/POPS... Tallahassee 49 63 30 48 / 0 10 0 0 Panama City 55 63 31 51 / 10 10 0 0 Dothan 51 59 26 46 / 30 10 0 0 Albany 51 57 25 44 / 20 10 0 0 Valdosta 47 63 25 46 / 0 10 0 0 Cross City 48 73 31 54 / 0 0 0 0 Apalachicola 54 65 34 50 / 0 10 0 0 && .TAE WATCHES/WARNINGS/ADVISORIES... FL...Cold Weather Advisory from 1 AM EST /midnight CST/ to 10 AM EST /9 AM CST/ Monday for FLZ007>019-027>029-034-108-112-114- 115-118-127-128-134-326-426. Freeze Watch from late Sunday night through Monday morning for FLZ108-112-114-115. GA...Cold Weather Advisory from 1 AM to 10 AM EST Monday for GAZ120>131-142>148-155>161. Freeze Watch from late Sunday night through Monday morning for GAZ120>131-142>148-155>161. AL...Cold Weather Advisory from midnight Sunday night to 9 AM CST Monday for ALZ065>069. Freeze Watch from late Sunday night through Monday morning for ALZ065>069. GM...Small Craft Advisory from 4 PM Sunday to 1 PM EST Monday for GMZ730-755-765-775. Gale Warning from noon Sunday to midnight CST Sunday night for GMZ751-752-770-772. Small Craft Advisory from midnight Sunday night to noon CST Monday for GMZ751-752-770-772. && $$ SHORT TERM...Reese LONG TERM....Reese AVIATION...Dobbs MARINE...Reese FIRE WEATHER...Reese HYDROLOGY...Reese ####018011496#### FXUS61 KBTV 131833 AFDBTV Area Forecast Discussion National Weather Service Burlington VT 133 PM EST Sat Dec 13 2025 .SYNOPSIS... A clipper passing to our north and upper level low over the Great Lakes will bring some light snow through the weekend, with locally heavier snow in parts of northern New York and in higher terrain. More light snow is expected for later Monday into Monday night. A warming trend will lead to the potential of mixed precipitation types towards the end of the week. && .NEAR TERM /THROUGH SUNDAY NIGHT/... As of 133 PM EST Saturday... * Locally gusty, heavy snow showers this afternoon in western St. Lawrence County. Otherwise, very light snow tonight into early Sunday, followed by upslope, northwest flow type of light snowfall for Sunday night. A busy period through Sunday night with regards to at least some chances of snow associated with three different systems in which heavier precipitation will be south of our area for a change. The only heavier type of snow is occurring at the time of this writing as we track a large, convective line of snow showers that is entering St. Lawrence County this afternoon. Upstream observations show brief reductions to a 1/4 mile visibility, and the fairly sharp reflectivity gradient suggests rapid changes in conditions with this likely snow squall. Progged CAPE in the 25 to 75 J/kg range will be supportive of snow squalls as the line moves into central portions of the county, such as in Potsdam. Thereafter, instability will tend to decrease along with the low level theta-e gradient becoming less well defined, such that an organized snow squall threat will diminish moving into the Adirondacks. Elsewhere, as we often see on convective days there has been a large area of very light snow blossoming with a fresh coating of snow expected for most of Vermont and the remainder of northern New York. This snow will tend to diminish this evening, hanging on last in northeastern Vermont. Thereafter, we'll see another round of light snow develop, this time associated with mid-level deformation on the northwest flank of the low pressure system passing well to our south and east. Because of the large scale upper level divergence tied to the intense upper level low over the Great Lakes, we might be able to squeeze out periods of light, accumulating snow tonight as higher mid-level relative humidity surges northward. Best chances of this would be during the overnight hours and across central and eastern portions of Vermont, but it is hard to rule out any part of Vermont seeing at least a trace of new snow through tomorrow morning. Finally, another minor snowfall will occur tomorrow night as the aforementioned upper level low ejects eastward and its trough axis passes by. The resulting northwesterly flow should be able to squeeze out snow showers which will be aided by cold low level temperatures supportive of effective snow growth in shallow clouds. With Froude numbers likely dropping under 0.5 at times overnight as an inversion level develops near mountain summit level, snow showers are expected to expand westward into the valleys although much of the snow shower activity will be in the foothills. QPF looks light given forcing is purely orographic with no replenishing deeper moisture being advected in, but a new coating to an inch of snow is plausible in the upslope areas of the Adirondacks and Greens. This overnight period also continues to look like the coldest weather of the next several days, with blustery winds of 10-15 MPH supporting wind chills in the single digits to teens below zero. && .SHORT TERM /MONDAY THROUGH MONDAY NIGHT/... As of 133 PM EST Saturday... * Below normal temperatures with mainly light snow showers Monday night Aside from some lingering snow showers, Monday continues to look cold and dry initially. Late in the day we continue to expect snow to develop in northern New York as the next shortwave trough comes in from the northwest. With no surface reflection, this system won't have much to work with regards to precipitation amounts. Compared to the system we're seeing today, thermal and pressure gradients are lackluster so even less organized precipitation is anticipated, but at least some light snow is probable areawide Monday night aside from perhaps southeastern Vermont. The one area of possibly heavier snowfall rates will be related to a modest lake band expected to develop off of Lake Ontario, which could poke into our far southern portions of northern New York before winds upstream turn westerly and the precipitation shifts to our south. If the west- southwesterly flow lingers a bit longer, snow amounts currently forecast in the coating to an inch range could be a bit higher, including areas farther downwind in the Adirondacks and central Green Mountains. It will remain below normal temperature-wise, with temperatures only recovering into the middle 10s to low 20s, but with light south winds and cloudiness overnight, Monday night won't be much colder than the daytime. && .LONG TERM /TUESDAY THROUGH SATURDAY/... As of 1258 PM EST Saturday...The weather pattern stays pretty active through much of next week. We'll see a brief stint of ridging Tuesday/Tuesday night, so outside of a few lingering mountain snow showers during the morning hours, it should be dry. Low pressure will slide by to our north on Wednesday, dragging a couple of fronts across our region. The result will be another round of showers, along with temperatures warming into the mid/upper 30s. So while the mountains should generally remain snow, the wider valleys will likely mix with or change to rain during the afternoon. Highest chances for precipitation will remain in northern areas, closest to the best forcing. More widespread precipitation then arrives later Thursday through Thursday night. There are still differences in model solutions with the timing/placement of this low pressure system and its associated fronts, but overall trend continues to keep the main low well to our north, with strong warm air advection occurring later Thursday into Thursday night, followed by a sharp cold front sometime on Friday. Have stayed close to the NBM for now given the continued model differences, but expect temperatures to warm into the upper 30s/low 40s, allowing snow to change over to rain for just about all but the highest elevations sometime Thursday evening/night. Considering how cold we've been, there are concerns that there could be a prolonged period of a wintry mix of snow/sleet/freezing rain before the changeover to rain, especially in the usual sheltered locations east of the Greens. We'll continue to monitor trends heading forward, and would recommend our partners and the public to do likewise, especially if travel is planned later Thursday/Thursday night. Regardless, colder air comes rushing back in Friday, changing precipitation back over to snow as it tapers to showers heading into the weekend. The other concern with this active pattern will be gusty winds. With several frontal passages, there are indications of strong low-level jets and the potential for these to mix down to the surface. At this point, Thursday looks to be the windiest day, with south winds gusting to 30 mph or more, especially in the Champlain Valley and the northern slopes of the Adirondacks. However, south winds also look to be gusty on Wednesday, followed by blustery west winds on Friday once the cold front moves through. This combined with precipitation, especially if we get any significant snow and/or freezing rain accumulation, could be impactful to both travel and utilities. && .AVIATION /18Z SATURDAY THROUGH THURSDAY/... Through 18z Sunday...A mix of conditions through the first 6-10 hours of the TAF period. First will be a period of light snow, which will be ongoing at the start of the forecast. Generally 4-6SM with occasional reductions to 2-3SM, through roughly 22z. Ceilings 3500- 4500 ft, lowering to 2500 ft in snow. Meanwhile, a lake enhanced band of moderate to heavy snow will move into the St Lawrence Valley around 19z and push eastward through the afternoon, affecting mainly KMSS/KSLK through 22z. Visibility likely reduced to 1SM or even lower as it moves through, with ceilings down to 1500 ft. This band should break up beyond KSLK. Snow generally winds down by 00z, but additional showers will be possible at KRUT/KMPV 04z-10z, with 2-4SM visibilities. Otherwise, ceilings remain MVFR/VFR 2500-3500 ft through 12z, then gradually improving through the end of the TAF period. S/SW winds 6-12 kt through 02z, with gusts to 25 kt possible, especially at KBTV/KPBG/KMSS. Winds then becoming light and variable after 02z, though there are some indications that a brief period of additional gustiness will be possible 02z-06z as frontal boundary moves through. Winds NW around 5 kt from 12z Sun onward. Outlook... Sunday Night: VFR. NO SIG WX. Monday: VFR. NO SIG WX. Monday Night: Mainly VFR, with areas MVFR possible. Chance SHSN. Tuesday: Mainly VFR, with local MVFR possible. NO SIG WX. Tuesday Night: VFR. NO SIG WX. Wednesday: Mainly MVFR, with areas VFR possible. Chance SHRA, Slight chance SHSN. Wednesday Night: Mainly MVFR, with areas VFR possible. Slight chance SHSN. Thursday: VFR. Chance SHRA, Slight chance SHSN. && .MARINE... Channeled southerly flow will develop later in the night and continue through the day, causing winds on the lake to be between 15-30 KTs. Winds decrease quickly this evening as flow turns westerly. They should be around and below 10 KTs by midnight. Waves will build up to around 2-5 feet by the afternoon, before they quickly diminish in the evening as winds drop. A few brief snow showers are possible today and tonight but they should be light and brief. && .EQUIPMENT... NOAA Weather Radio station WXM-44, transmitting from Mt. Ascutney, Vermont, on frequency 162.475 MHz is non-operational at this time. NWS technicians have diagnosed the problem, but repairs will likely not be able to occur for quite some time due to circumstances beyond our control. Therefore, the time of return to service is currently unknown. The following NOAA Weather Radio transmitters may be able to provide service during this outage: WWG 50 from Burke Mtn, VT at 162.425 MHz and WNG 546 from Hanover, NH at 162.525 MHz. Equipment malfunctions at the Colchester Reef meteorological station will likely leave it inoperable for an extended period of time. This site is not serviced by the NWS. Technicians do not currently have an estimated return to service for this station. Use extra caution when navigating the broad waters of Lake Champlain, and please contact us if you observe winds significantly deviating from the forecast. && .BTV WATCHES/WARNINGS/ADVISORIES... VT...None. NY...None. && $$ SYNOPSIS...Kutikoff NEAR TERM...Kutikoff SHORT TERM...Kutikoff LONG TERM...Hastings AVIATION...Hastings MARINE...Myskowski EQUIPMENT...Team BTV ####018004784#### FXUS63 KIWX 131834 AFDIWX Area Forecast Discussion National Weather Service Northern Indiana 134 PM EST Sat Dec 13 2025 .KEY MESSAGES... - A period of accumulating snow (1-3", locally higher far south) for areas mainly along and south of US 30 in IN, and areas south of US 24 in nw OH, through the early evening. - 1-3" of lake effect snow expected tonight into Sunday morning in northwest IN and southwest MI. - Below zero wind chills tonight and Sunday night, with values of -15 to -20 south of US-30 tonight. - Warmer temperatures by Tuesday and Wednesday. && .DISCUSSION... Issued at 133 PM EST Sat Dec 13 2025 Accumulating snow moving through the southern half of the area this afternoon into early this evening. A mid level perturbation and associated corridor of pacific moisture is driving this swath of snow, with noted baroclinic enhancement within the right entrance region of a ~140 kt upper level jet. These features are phasing with an impressive polar vort lobe flirting with the northern shores of Lake Superior. The quick clipper movement likely holds snow totals to 1-3" for the southern half of the forecast area, with locally 3-5" up against our bordering counties with IND. Sfc temps in the mid-upper teens will make for slick travel into the early evening. Arctic air fully wraps in tonight into Sunday with dangerous wind chills and LES in our northwest flow snow belts. Strong dry advection from the Upper Midwest and a low DGZ favor small flake size within the LE plume despite impressive delta T magnitudes, though there could be a period later this evening into early Sunday morning where better flake size will be possible. Overall expectations remain unchanged with snow amounts generally in the 1- 3" range in the South Bend area and southwest MI. Reduced visibilities and snow covered roads will create hazardous travel in spots. This lake plume likely keeps wind chills from reaching advisory criteria (15 below or colder) for most locations along and north of US 30, with areas to the south in IN experiencing wind chills as cold as -20F Sunday AM with no changes to the Cold Weather Advisory. A warm advection regime develops Sunday night and continues through mid week as sfc high pressure settles off to the southeast under flattening flow aloft. With that said, sub-zero wind chills will persist into Sunday night and Monday morning as the near sfc arctic wedge is slow to erode with increasing southwest winds. Probs for advisory or colder wind chills by this time are relatively low per HREF/NBM probs, but any minor adjustments to temps and winds could easier push values to -15F or colder for a time. Dry otherwise as WAA induced snow likely bypasses northeast later Sun night-Monday. && .AVIATION /18Z TAFS THROUGH 18Z SUNDAY/... Issued at 1245 PM EST Sat Dec 13 2025 Snow has overspread much of northern Indiana this afternoon, largely in response to the activation of a mid/upper level frontal zone by an upstream short wave. Latest observational and short range guidance trends guidance to support KFWA and points southward for best snowfall accumulations (generally in the 1 to 3 inch range at KFWA). Elevated lift and top-down saturation appears to have favored some seeder-feeder processes at KSBN with brief redevelopment of lake enhanced snow showers downstream of the main synoptic system. However, it still appears KSBN will be on the northern periphery of system snow, with low confidence in any notable duration periods with anything lower than MVFR vsbys. System snow will depart to the east this evening which will be followed by quick transition late evening/overnight to lake effect snow showers. KSBN should see some periods of vsby restrictions tonight into early Sunday. Cold temperatures in boundary layer and very shallow based DGZ should allow for small flake size that could be more efficient vsby reducers. Some lake effect snow showers are possible at KFWA overnight for a time, but confidence is too low to include at this time. Inversion heights should sharply drop mid morning Sunday with lake effect snow showers expected to taper quickly. && .IWX WATCHES/WARNINGS/ADVISORIES... IN...Cold Weather Advisory from midnight tonight to 1 PM EST Sunday for INZ013-015-020-022>027-032>034. Winter Weather Advisory until 7 PM EST this evening for INZ020- 022-023-032>034. OH...None. MI...None. MARINE...Small Craft Advisory until 10 PM EST Sunday for LMZ043-046. && $$ DISCUSSION...Steinwedel AVIATION...Marsili ####018008245#### FXUS66 KMTR 131835 AFDMTR Area Forecast Discussion National Weather Service San Francisco CA 1035 AM PST Sat Dec 13 2025 ...New AVIATION... .KEY MESSAGES... Updated at 111 AM PST Sat Dec 13 2025 - Dense fog impacts are expected through the morning in the Interior North Bay and East Bay Valleys as well as coastal locations - Wet conditions return next week && .UPDATE... Issued at 859 AM PST Sat Dec 13 2025 Fog and stratus persist across the North Bay and interior East bay valleys, in addition to the 101 corridor across San Mateo County and the southern Monterey Bay region. The southerly surge is moving parallel to the Sonoma County coastline, but it is somewhat detached from the immediate coastal regions, with the primary areas of stratus surge impacts being along the coast south of Point Sur and the San Mateo County coastline south of Half Moon Bay. Stratus is expected to continue diminishing through the morning and afternoon hours, lingering at the immediate coastal regions and parts of northern and eastern Contra Costa County. DialH && .SHORT TERM... Issued at 111 AM PST Sat Dec 13 2025 (Today and tonight) Today's main impact will be a tale of two fogs: advection and radiation. Let's start with the persistence side of the forecast, or what has been happening. Portions of the region will continue to be affected by tule fog (a type of radiation fog) as it seeps out of the Central Valley through neighboring gaps and passes which will continue to facilitate below normal temperatures. There is also a southerly surge underway which will bring more traditional advection fog to coastal locations. This will not only be a change to the warm, sunny afternoons that have been observed the last week, but also to the cold overnight conditions that have been made possible by clear skies which allow for radiational cooling. We will continue to monitor the evolution of both of these through the morning to see if the Dense Fog Advisory that is in effect through 11AM for North Bay and East Bay Interior Valleys needs to be extended in area, time, or both. Consider delaying unnecessary travel until visibilities improve. If travel is necessary, make sure to use your low-beam headlights, increase following distance between vehicles, and allow extra time and patience. Elsewhere, sensible weather will yield temperatures up to 15 degrees above normal as the region remains under the influence of upper-level longwave ridging. Offshore flow will also continue with high pressure across the Great Basin and a coastal trough off the West Coast. && .LONG TERM... Issued at 111 AM PST Sat Dec 13 2025 (Sunday through Friday) The aforementioned upper-level longwave ridge will exit to the east Sunday, giving way to zonal flow for most if not all of the long term forecast. Passing disturbances to the north and an increase in precipitable water and integrated vapor transport values will renew rain chances as early as Monday with no clear cut dry day beyond that. Rainfall in the beginning of the week is expected to be light and beneficial for those who are lucky enough to get any. This will also act to disrupt the pattern that we have been in that has allowed for relentless tule fog. Towards the tail end of the long term forecast period, a relatively more significant system is forecast as a surface low pressure system and its attendant cold front encroach the California Coast. It is too soon to delve into the specifics, but expect a change in the pattern and a return to wet conditions next week. This weekend would be a great time to clean out gutters and trim trees away from your home and power lines. But wait, there's more! Beyond the long term forecast of seven days, it continues to be advertised that there's a moderate risk of heavy precipitation and high winds Saturday, December 20th through Friday, December 26th. This will not only be important for daily life, but also holiday travel. && .AVIATION... (18Z TAFS) Issued at 1035 AM PST Sat Dec 13 2025 It's going to be slow to very slow going today regarding fog and low stratus /VLIFR-IFR/ mixing out in the North Bay and the East Bay. With offshore pressure gradients 8.0 mb WMC-SFO, 1.5 mb SAC- SFO and weak surface low pressure located over the coastal waters, the surface to near surface pattern will continue to strongly favor tapping the Central Valley source of cold air, fog and low stratus today. With a weak 500 mb trough overhead and a weakening of the lower level temperature inversion, it's up to the Sun to do what it can to try to break through the solid pool of incoming fog and low stratus; pilot reports indicate ~ 1,000 feet thickness from bases to tops. Peak surface heating this time of year is ~ 3 pm, only 5 hours from now. Away from the current fog and stratus, the sky is mainly VFR with a few lingering cold pockets of air around the Bay Shoreline and the south San Francisco Bay. Maritime fog and stratus /LIFR-IFR/ continues to brush along the coastline; local, limited inland intrusions remain possible with this area of fog and stratus through late morning and afternoon. Below normal water vapor distribution mainly in the mid to upper levels of the troposphere supports nocturnal radiative cooling tonight to early Sunday, this will reinforce the ongoing Central Valley tule fog/low stratus. Neither the GFS nor the ECMWF are forecasting cirrus tonight and Sunday morning. Light offshore winds will quite likely transport fog and low stratus to areas that have nightly/daily fog and low stratus. Vicinity of SFO...A patch of stratus lingers just north of KSFO nudged southward and westward with an influx of colder air arriving on light NE-E surface winds. This patch should continue to mix out, favoring moderate to high confidence VFR for the the remainder of the morning and afternoon. Surface wind may shift back around to light northwest during the afternoon to early evening, then back to light northeast tonight and Sunday morning. Low confidence VFR forecast tonight and Sunday morning primarily because of the meso- scale models having difficulty forecasting this ongoing pattern. SFO Bridge Approach...Low stratus clouds are getting nudged southward from influx of NE-E winds arriving at KSFO terminal. Cold surface air continues to wobble around the SF Bay, and this may result in redevelopment of low stratus patches back in the approach zone from late morning to early afternoon. Otherwise higher probability of VFR for the afternoon to early evening. Slantwise visibility may be reduced to moderate to poor at sunset and sunrise due to hazy conditions. Monterey Bay Terminals...LIFR due to stratus and mist rotated inland from the northwest reaching KMRY, this will need another ~ 1/2 hour to mix out to VFR at KMRY. Otherwise moderate to high confidence VFR for the afternoon. Low to moderate confidence IFR due to stratus developing tonight and Sunday morning. && .MARINE... (Today through Thursday) Issued at 859 AM PST Sat Dec 13 2025 A weak surface low pressure circulation over the outer coastal waters will result in gentle to moderate southerly breezes and the potential for dense fog today. Winds will veer to become northwesterly tomorrow night. Seas will remain moderate through Monday, building to become rough in the outer waters and northern inner waters by Tuesday. Several disturbances passing to the north next week will bring renewed rain chances and wind shifts. && .MTR WATCHES/WARNINGS/ADVISORIES... CA...Dense Fog Advisory until 11 AM PST this morning for CAZ506-510. PZ...None. && $$ SHORT TERM...Sarment LONG TERM....Sarment AVIATION...Canepa MARINE...Canepa Visit us at www.weather.gov/sanfrancisco Follow us on Facebook, X, and YouTube at: www.facebook.com/nwsbayarea x.com/nwsbayarea www.youtube.com/nwsbayarea